        (throw (IllegalArgumentException.
                 (format "Range start %d must be less than range end %d"
                         start end))))
-     (data/content-stream block start end))))
+     (io! (data/content-stream block start end)))))
 
 
 (defn read!

(defmacro ^:private measure-method
  "Anophoric macro to measure a store method."
  [[method-kw args] & body]
  `(meter/measure-method*
     ~'store ~(name method-kw) ~args
     (fn body# [] ~@body)))


(defn list

  [store & opts]
  (let [opts (args->map opts)
        timeout (:timeout opts 10000)]
    (when-not (pos-int? timeout)
      (throw (IllegalArgumentException.
               (str "Option :timeout is not a positive integer: "
                     (pr-str timeout)))))
    (letfn [(stream->seq
              [s]
              (lazy-seq
